I need transmission rebuilding help for my 1991 Aerostar.

[htbird]

I have a '91 Aerostar with the 4.0L and A4LD. I am tearing it down right now, and I have the same problem that Brain had in the A4LD diary , namely that the input shaft is stuck in the OD drum, and won't come out! Anybody have any idea how to get this thing loose? The transmission had no 3rd or 4th gear. Thanks

 

[Glacier991]

Stuck in the drum or the splined OD sprag carrier? Either way I should think a brass drift and a hammer should pound it out.... if not just get a new drum and shaft... I can give you an online link for a seller of used parts...

 

[Brain]

When I finally got mine apart by 'ing it, everything up in the front was a loss...the shaft was grooved where a brass bushing was heat/friction-welded to it, the OD drum and planet carrier were a complete loss as well.

I'm taking it for granted that you couldn't remove the input shaft like the manuals say, but instead lifted the bellhousing off with the shaft still in place. That's what I had to do.

 

[htbird]

Yes, that's exactly what I did. I thought it was kind of strange because it sounded like the input shaft was supposed to just slide out. Anyway, a little rubber hammer action and it came apart. But inside was not pretty. The whole OD section is pretty toasted. The OD clutch adapter, or castle washer as you guys like to call it, was apparently spinning around on the drum. I assume that its not supposed to do that! The needle bearing is disintegrated, and the back of the planetary is all ground down. So I can see where the $400+ in hard parts comes from.
But the rest of the stuff looks pretty good. I think this thing was just rebuilt about 3 years ago, because there's a guy's name and a date (March something 2001) written on top.
I just got the spring compressor from Advance Auto you recommended, and it worked as advertised. Next up, I'm going to get a rebuild kit and start doing what i can. Can't afford hundreds of dollars all at once on parts just now.
I had a thought : I could get a whole transmission from the local pull-a-part place for $70, and maybe try to salvage an OD drum, etc? Probably not a real good idea, huh?
And oh yeah, theres several trans parts places here in Atlanta I can go to. But I don't think they like me much

 

[Glacier991]

I'd just do it in stages... disassemble it and bag each component and strip the case. having toasted it and with metal about.... I'd want to clean the case real good... you can leave the valve body for now (other than just removing it and bagging it I mean), but it will need a complete teardown and good cleaning and rebuild. There is a guy (MMERLIN) selling used A4LD parts on ebay for about half of new (that's his business)... the OD drum can be had there for about $30 as I recall. An input shaft about $8. You are going to need a whole new OD planetary carrier and the beefed up OD planetary.... and front sprag... I'd at least go new on the sprag... the OD planetary is your call - no "right vs wrong " here. Take your time a disassemble and clean each component really well and evaluate them for reuse. Reassemble by component from the back forward (or however you want). The Diary was intended to give you an idea how *I* did it... you might want to go about it differently.

 

[Brain]

Yep, if it isn't damaged it is supposed to slide right out and right in.
As for reusing parts, one you get that metallic mud in the system you have to be sure to get all of it out (many hours of cleaning or it might just be a very temporary fix).

Here's my ongoing saga of my A4LD rebuild (ended up being a real project because I always want to modify something and make it 'better'). There is lots of info on parts and some things to look out for when using used parts as well as some things that might come off as rants ; ) There are a lot of pictures, but it is pretty educational.
http://www.explorerforum.com/forums/showthread.php?t=117793&page=1&pp=20

At the very end there is a link to an 'updated' OD planetary that has the "improved" guide but it requires using the latest spring retainer. I don't think you'll find that on a junked unit.

 

[htbird]

Well, after more disassembling and "bagging," I've found more problems. The forward clutch is all burned up. I counted 9 steel rings and 3 friction rings. (as in, there all burned up and gone.)I guess this is the source of all the black stuff in the fluid. I thought there was only supposed to be 6 rings!? I'm beginning to wonder why I ever started this! My wife says I'm "having fun." Maybe I am, but I wasn't expexting this much damage. The junkyard tranny's sounding better all the time. And thank you very much Glacier for the pictures! I'd be lost in space without them. Enough for one night.
One last question: would the forward clutch be the reason I wasn't getting the 2-3 shift?

 

[Brain]

Probably not as the forward clutch is engaged in all forward gears. The 2-3 upshift comes from the intermediate band disengaging while the reverse/high clutch is engaging.

 

[htbird]

Finished disassembling the clutches. Figured out what the deal was with the forward clutch rings. The friction rings are metal inside and with all the friction stuff gone they look like steel rings. Anyway, the forward drum is all black looking. I could probably reuse it, but I'm not sure. Forward piston is suspect too.
I have a question for all you tranny gurus. There's a part shown in the manuals behind the OD sun gear. It's Ref. # 189 Part #7D235 Race-Sun Gear Thrust Brg.-Rear I didn't find any evidence of this thing anywhere. Am I crazy, or was it just all ground away/disintegrated? The needle bearing was all messed up. But luckily I think all the metal junk stayed inside the OD drum.
Here's a list of what i think i nees so far:
OD Drum
OD Clutch Adapter(castle washer)
OD Planetary
OD Needle Bearing #2
the "tin plate" washer
OD one-way clutch/sprag
that rear race thing?
and possibly:
Forward Drum
Forward Piston
Thats in addition to all the basic stuff.
Glacier, maybe you could direst me to the ebay guy for some cheap parts.
Thanks guys. H.

 

[Glacier991]

The design of that sun gear thrust bearing has changed over the years.. Brain and I have discussed that. In the one I took out in my rebuild I could actually maneuver it out... in the new planetary is was build into it and non-removeable. In the newest one I bought you hardly realize it is there til you push on it and rotate it.

 

[htbird]

I just figured that out myself looking at the ford manual. I guess its considered part of the plant itself. However, the #2 needle bearing was completely gone. Therefore, the planet was riding on the ring gear with nothing inbtween it. Like I said, the back of the planet is all scored, but it still works. I'll replace it.
How about the forward drum? Is it normal for it to be all black looking? Looks like there was some serious heat there.
I've got all kinds of concerns...center support, governor area, pump. I think I'm going to call this "Project Broken-Tranny." But I'm not as bummed out as I was yesterday. I think I'll take it easy for a day or two and study some more.

 

[Brain]

Be sure to check the pump snout that the OD drum rides on...mine was pretty scarred up so I had to get a new pump. You also want to check the bushing inside the pump snout because that is a pressure-sealing element - too much wear and you will start burning up torque converters because there will be too much TCC fluid leakage.

The bearing you are talking about goes between the OD sun gear and the OD planet carrier. The early ones had a three part bearing (two races and an open needle bearing) and you could remove the race that went towards the sun gear. The later ones looked like this:

It is the part that is under the planet gears and above the splined area in the center. You can see that it is enclosed and non-removable.

BTW, the brass bushing that was friction-welded onto my input shaft was from the sun gear (that's what kept me from getting it out before removing the bellhousing) - the center of this:

 

[Glacier991]

And yes the forward drum is rather blackish looking. It's normal (cast drum)

 

[Brain]

This thing?

 

[htbird]

I guess I could reuse it then. So mostly we're looking at OD parts. Maybe it won't be TOO expensive. I'm definitely going to get the thrust washer kit, but I don't know about all these bushings, and how to replace them. Might just leave them as is. I just want to get this thing moving. Don't really want to replace everything, but then again, I want it to work! I'm having nightmares about putting the transmission back in, and it not working, having to take it back out, and then figuring out htat I left out some little dinky washer or something. This is definitely a learning experience.